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5.9Medium

Mikrotik Routeros

CVE-2017-6297

The L2TP Client in MikroTik RouterOS versions 6.38.3 and 6.37.4 does not enable IPsec encryption after a reboot, which allows man-in-the-middle attackers to view transmitted data unencrypted and gain access to networks on the L2TP server by monitoring the packets for the transmitted data and obtaining the L2TP secret.

What this means for your business

  • It affects Mikrotik Routeros. It matters if your company, or a supplier that handles your data, runs it.
  • Code showing how to exploit it has been published, but real attacks have not been confirmed.
  • An attacker can use it remotely, over a network, without a login, and without anyone at your company clicking anything.

What to do

  1. 1Check whether your company or your suppliers run Mikrotik Routeros, and which version. The affected versions are listed further down this page.
  2. 2If you do, follow the vendor's guidance. No patch reference has been published yet.

Not sure if your company is exposed?

Fastnexa’s certified penetration testers can check whether attackers could use this flaw, or others like it, against your websites, apps and network. The full test is free for our first 10 founding clients until 31 December 2026.

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Scoring

CVSS
5.9 (v3.0)
Vector
CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N
Weakness
CWE-311
Assigned by
cve@mitre.org

Dates

Published
2017-02-27
Last modified
2026-09-16
Sources
NVD

Affected products

  • Mikrotik Routeros6.37.4, 6.83.3

As listed in the NVD configuration data. Not a statement about your estate.

References